Need alot help here

Hello, im a nub, and im trying to learn torque script recently from this book, i have a brief knowledge in C++.
everything is ok until i reach Chapter4, its really hard for me to understand the concept of the codes, i will list one of the code from that chapter and label my question, so this will be long, i apologize for that:

i delete all comments just coz it make this thread looks messed up
my question will be inside () besides the statement

$usageFlag = false;
$logModeEnabled = true;
SetLogMode(2); (what is that?)

function OnExit() (says to be pass error into this function but how?)
{
}

function ParseArgs()
{
for($i = 1; $i < $Game::argc ; $i++) (what is how can $Game::argc work her if it hasn't given a value?)
{
$currentarg = $Game::argv[$i];
$nextArgument = $Game::argv[$i+1];
$nextArgExists = $Game::argc-$i > 1;
$logModeEnabled = false;

switch$($currentarg)
{
case "-?":
$usageFlag = true;
$argumentFlag[$i] = true;
case "-h":
$usageFlag = true;
$argumentFlag[$i] = true;
}
}
}
function Usage()
{
Echo("\n\nemaga4 command line options:\n\n" @ " -h, -? display this message\n" );
} ( i actually dont understand how @ works)

function LoadAddOns(%list)
{
if (%list $= "")
return;
%list = NextToken(%list, token, ";"); (NextToken? come from where?)
LoadAddOns(%list);(where is LoadAddOns from)
Exec(%token @ "/main.cs"); (adjust if im wrong, so is %token from main.cs and this statement is to execute it?)
}


ParseArgs();

if ($usageFlag)
{
EnableWinConsole(true); (one again what is EnableWinConsole and Usage, Quit)
Usage();
EnableWinConsole(false);
Quit();
}

else
{

for ($i = 1; $i < $Game::argc; $i++)
{
if (!$argumentFlag[$i])
Error("Error: Unknown command line argument: " @ $Game::argv[$i]);
}
if (!$logModeEnabled)
{
SetLogMode(6); (once again SetLogMode?)
}

$pathList = $addonList !$= "" ? $addonList @ ";control;common" : "control;common";
(hoho this part is one of the confuseist thing i ever seen)
SetModPaths($pathList);(SetModPaths? what is that)

Exec("common/main.cs");

Exec("control/main.cs");

Echo("--------- Loading Add-ons ---------");

LoadAddOns($addonList);

Echo("Engine initialization complete.");

OnStart();
}

kk thatz all, well not all, it just one of the codes that i confused with lol...
and if there is some question made any of u 'lol' in front of ur screen, ill lol with u too :)
and thanks for check out my nub questions, ty more for give me the answer!